Expression of beta-galactoside alpha 2,6 sialyltransferase blocks synthesis of polysialic acid in Xenopus embryos.

Polysialic acid is a developmentally regulated carbohydrate structure found on neural cell adhesion molecules (NCAM). Expression of beta-galactoside alpha 2,6-sialyltransferase in Xenopus embryos, by injection of mRNA, prevents the polysialylation of NCAM, presumably by introducing a different type of sugar linkage that terminates chain elongation. Abnormalities in neural development result from this treatment, but in general the body plan of the injected embryos is not severely affected. The results provide evidence that the mis-expression of glycosyltransferases can be used to interfere with the normal pattern of glycosylation in whole organisms.